While dreaming, the Pineal gland in the brain produces the chemical called DMT (Dimethyl Tryptamine). This chemical is the reason you dream. People often extract this chemical from some barks in plants, and then smoke the chemical... It creates a very psychedelic experience, and people report seeing gods, or meeting sentient beings, etc.

Based on this, it is 100% possible to travel to some sort of "astral plane" while dreaming. I wouldn't necessarily call it an astral plane, but it is sort of a representation of your personality in a dream form.. You will be talking to a being that teaches you everything about the world, and you won't be able to explain it to anyone.

Next time you lucid dream, definitely try!